Tunable and Well-Defined Bimodal Porous Model Electrodes for Revealing Multiscale Structural Effects in the Nonaqueous Li-O2 Electrode Process
Tunable and Well-Defined Bimodal Porous Model Electrodes for Revealing Multiscale Structural Effects in the Nonaqueous Li-O2 Electrode Process
复制标题
可调谐且定义明确的双峰多孔模型电极，用于揭示非水 Li-O2 电极过程中的多尺度结构效应
DOI：
10.1021/acs.jpcc.0c10446
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Ken Sakaushi*
中科院分区：
文献类型：
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作者：
Yosuke Hara;Manai Ono;Shoichi Matsuda;Kazuki Nakanishi;Kazuyoshi Kanamori;Ken Sakaushi*
多孔结构是非水锂氧（Li-O2）电极过程的关键，由于其在可逆能量存储中具有高理论能量密度的应用而引起了巨大的兴趣。然而，它仍然是具有挑战性的，以了解最佳的多孔结构，以获得高可逆性的反应。一个主要原因是由碳质材料组成的标准电极的不稳定性和不确定的多孔结构，并且这个问题阻碍了揭示复杂电极过程的基本机理。在这里，我们开发了一种新的合成策略来设计具有受控双峰多孔结构的纯金属镍的单片电极。本工作旨在研究无碳/粘合剂稳定模型电极下双峰大孔结构在Li-O2电极过程中的基本影响。其结果是，我们发现，根据多尺度的结构配置，双峰大孔结构的关键性能，如氧化还原介质的效率，放电过电位，和循环寿命的显着影响。这项工作表明，合理设计的稳定和导电的多孔材料是一个有前途的方法来研究高度复杂的电化学反应在多孔电极，并提出了新的指导方针，为进一步发展的层次结构的电极向先进的电化学系统。
Porous architecture is key in the nonaqueous lithium–oxygen (Li–O2) electrode process, which is attracting huge interest because of its application in reversible energy storage with high theoretical energy density. However, it is still challenging to understand the optimal porous structure to obtain high reversibility of the reaction. One main reason is because of instability and undefined porous structures of standard electrodes consisting of carbonaceous materials, and this issue hinders from unveiling the fundamental mechanism in the complicated electrode process. Here, we developed a new synthetic strategy to design monolithic electrodes of pure metallic nickel with controlled bimodal porous structures. The present work aims to investigate the fundamental effects of the bimodal macroporous structure in the Li–O2electrode process under carbon-/binder-free stable model electrodes. As the result, we found that, depending on the multiscale structural configurations, the bimodal macroporous structure gave significant influences to key properties, such as the efficiency of redox-mediators, discharge overpotential, and cycling life. This work indicates that the rational design of stable and conductive porous materials is one of the promising approaches to investigate highly complicated electrochemical reactions in porous electrodes and suggest new guidelines for further development of hierarchically structured electrodes toward advanced electrochemical systems.